Gas turbine engine with a diffuser cavity cooled compressor

A method of cooling a compressor of a gas turbine engine comprising:

• providing a flow of compressed air from the compressor of a compressor section to a diffuser cavity through a stage of discharge nozzles supported by an outer discharge nozzle case positioned outward of the stage of discharge nozzles along a radial direction and an inner discharge nozzle case positioned inward of the stage of discharge nozzles along the radial direction, wherein a combustion section comprises the diffuser cavity and the stage of discharge nozzles;
• providing a cooling airflow from the diffuser cavity to a cooling air passage defined in a forward spool section of a high pressure spool, the high pressure spool drivingly connected to the compressor, the high pressure spool further comprising a central spool section that is radially inward of the combustion section;
• and
• providing the cooling airflow from the cooling air passage to an aft-most compressor stage of the compressor of the compressor section to cool the aft-most compressor stage of the compressor;
• wherein the forward spool section comprises a forward spool member and a shield member, wherein the shield member is positioned adjacent to the forward spool member, and wherein the shield member and the forward spool member together define the cooling air passage, the shield member rotatable with the forward spool member;
• wherein a compressor discharge pressure seal is formed in part by the central spool section of the high pressure spool, the central spool section extending aft from the compressor discharge pressure seal, and the compressor discharge pressure seal is formed in part by the forward spool section, the forward spool section extending forward from the compressor discharge pressure seal and the central spool section to the aft-most compressor stage of the compressor;
• and
• wherein the inner discharge nozzle case defines an opening forward of the compressor discharge pressure seal and the central spool section, the opening providing the cooling airflow from the diffuser cavity to the cooling air passage, the compressor discharge pressure seal in contact with the cooling airflow, and
• wherein the forward spool member further comprises one or more thermal transfer features on a surface opposite a surface defining, at least in part, the cooling air passage.